Whitney Houston's 'Secret' Son?

March 9, 2012— -- At Whitney Houston's funeral, in a pew reserved for family, a young man sat beside the singer's daughter, Bobbi Kristina, and mother, Cissy Houston.

He was 22-year-old Nick Gordon. Though not related by blood to Houston, Gordon was "like a son to her," her brother, Michael Houston, told ABCNews.com.

A source close to Houston told ABCNews.com that Gordon was never legally adopted by the singer nor was he left anything in her will. Instead, Houston left her entire estate to her only child, Bobbi Kristina Brown, who has to wait until she's 30 to inherit everything.

According to sources close to the family and a TMZ report, Houston invited Gordon to live with her more than 10 years ago after learning that his birth mother could no longer care for him. She raised him alongside her daughter, who considers him her brother, according to the celebrity website Hollywood Life.

Reached by phone, Gordon declined to comment on his relationship with Houston, saying, "Everything that me and her went through will go to the grave with me."

But his closeness with the family is apparent on Twitter. On Dec. 26, Bobbi Kristina posted a picture of Gordon sitting between her and her mother in the back of a car. It was accompanied by the following tweet: "Mom, @ndgordon (: & I on the way to the airport friday ! (: #NYCBABYYYYY<3 home home home"

Bobbi Kristina and Gordon documented other interactions on Twitter as well. In September, Bobbi Kristina wrote: "Hello my dears ! (: how is everyone?! blessed beautiful day. out with @ndgordon :)) lunch& a movie. (: #Godissogood!"

In November, she wrote, presumably about Gordon: "I love sleeping with big brudder (: only person that helps my insomnia B!! Hah (: #teamfamilia!"

In December, Gordon posted a photo of him with his arm around Bobbi Kristina, along with the caption "@ndgordon (his Twitter handle) baby sis @REALbkBrown (Bobbi Kristina's Twitter handle)"

Earlier, he wrote "watching drum line with the lil sis @realbkbrown " Bobbi Kristina later posted the tweet on her page.

After Houston's sudden death Feb. 11, Gordon again turned to Twitter to express his grief.

"Rest in peace," he wrote, followed by "She has always had the most loyal fans and will continue to. Thank you" and "The Legend will always and forever live on."

He then thanked his 5,000-plus followers for their support.

From records obtained by ABCNews.com, it appears that Gordon, a partner in a tech company, still lives in the Houston family home outside Atlanta.

But TMZ is reporting that Houston's mother, Cissy Houston, is trying to boot him out because she believes he's a bad influence on Bobbi Kristina.

A rep for Cissy Houston did not immediately respond to a request for comment.

Gordon responded to the TMZ report with a tweet: "Wow you can't believe anything the media says. First time I heard any of this." He added, "God always prevails."

From his Twitter feed, it's clear Gordon remains close with Bobbi Kristina. "Happy Birthday ... I love you," he wrote to her on March 4, her 19th birthday.

Then, on her behalf, he thanked everyone for her birthday wishes.